Answer:
Mg²⁵ = 10.00%
Mg²⁶ = 45.04%
Mg²⁴ = 44.96%
Explanation:
Given data:
Atomic mass of Mg²⁶ = 25.983
Atomic mass of Mg²⁵ = 24.986
Atomic mass of Mg²⁴ = 23.985
Abundance of Mg²⁵ = 10.00%
Abundance of Mg²⁶ = ?
Abundance of Mg²⁴ = ?
Solution:
Average atomic weight of Mg = 25.983 + 24.986+ 23.985 / 3
Average atomic weight of Mg = 74.954/3
Average atomic weight of Mg = 24.985 amu
Abundance of
Mg²⁵ = 10.00
Mg²⁶ = x
Mg²⁴ = 100- 10 - x = 90 -x
Formula:
Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) + (abundance of 3rd isotope × its atomic mass) / 100
24.985 = (0.1×24.986)+(90-x×23.985) + ( x ×25.983 ) /100
24.985 = 249.86 + 2158.65 - 23.985x + 25.983x / 100
24.985 = 2408.51 + 1.998 x / 100
2498.5 = 2408.51 + 1.998 x
1.998 x = 2498.5 - 2408.51
1.998 x = 89.99
x = 89.99 /1.998
x = 45.04
Now we put the value of x:
Mg²⁵ = 10.00
Mg²⁶ = x (45.04)
Mg²⁴ = 90 -x (90 - 45.04 = 44.96)
Answer:
Oxygen is oxidized and hydrogen is reduced.
Explanation:
Let's consider the redox reaction during the electrolysis of water in an electrolytic cell.
2 H₂O ⇒ 2 H₂ + O₂
The corresponding half-reactions are:
2 e⁻ + 2 H₂O ⇒ H₂ + 2 OH⁻
2 H₂O ⇒ O₂ + 4 H⁺ + 4 e⁻
Oxygen is oxidized since its oxidation number increases from -2 to 0.
Hydrogen is reduced since its oxidation number decreases from +1 to 0.
Answer is "C".
<em><u>Explanation
</u></em>
Single replacement reaction is a type of reaction which one reactant reacts with another and makes a product by replacing one element by another.
Mg (Magnesium) reacts with Al₂O₃ (Aluminium oxide) and produces MgO (Magnesium oxide) and Al (Aluminium) as products. Here Al is replaced by Mg. Reaction is
Mg + Al₂O₃ → MgO + Al
To balance the reaction equation, both left and right hand sides should have same number of atoms in each element.
Here,
<em>Left Hand Side has </em> <em>Right Hand Side has</em>
Mg = 1 atom Mg = 1 atom
Al = 2 atom Al = 1 atom
O = 3 atom O = 1 atom
First step : balance the O atoms in both sides. To do that "3" should be added before MgO.
Second step : After balancing O atoms, there will be 3 Mg atoms in right hand side. Hence to balance Mg atoms again "3" should be added before Mg in left hand side
Third step : as the final step balance the Al atoms by adding "2" before Al in the right hand side.
Then final balanced equation should be
3Mg + Al₂O₃ → 3MgO + 2Al
Mass = moles x molar mass
so mass of 6 moles of h2 is: 6×1×2 = 12g
B 1.2g/mL just look at a graph and pin point those answers
